Proper storage of solder paste is crucial to maintain its quality. Here are the steps and considerations:
1. Temperature
Solder paste should be stored in a refrigerator. The ideal storage temperature is usually between 0 - 10°C (32 - 50°F). Storing at lower temperatures helps to slow down the chemical reactions and the aging process of the solder paste.
2. Packaging
Keep the solder paste in its original sealed packaging as much as possible. The packaging is designed to protect the paste from air, moisture, and contaminants.
If the original packaging is damaged, transfer the remaining solder paste to an air - tight container. For example, you can use a small plastic container with a tight - fitting lid.
3. Humidity
The storage area should have low humidity. High humidity can cause the solder paste to absorb moisture, which may lead to problems such as spattering during the soldering process, poor wetting of the solder, and an increased risk of oxidation. A relative humidity level below 60% is generally recommended.
4. Shelf Life and Usage
Solder paste has a limited shelf - life. Even under ideal storage conditions, its quality will deteriorate over time. Check the manufacturer's instructions for the recommended shelf - life, which is typically around 6 - 12 months from the date of manufacture.
When you take the solder paste out of storage for use, allow it to come to room temperature before opening the package. This helps to prevent condensation from forming on the paste, which could also affect its quality. Let it sit at room temperature (around 20 - 25°C or 68 - 77°F) for at least 2 - 4 hours, depending on the volume of the paste.
5. Avoid Contamination
Keep the storage area clean and free from dust, metal filings, and other contaminants. These can get into the solder paste and affect its performance or cause defects during soldering.
Do not store the solder paste near chemicals that could react with it, such as strong acids or alkalis.
